“资本是一个活生生的矛盾”——对马克思一个重要命题的当代解读

要科学回答2008年国际金融危机的发生根源,就要深刻认识马克思的“资本是一个活生生的矛盾”的命题.在马克思看来,为了获取剩余价值,资本必然会推动生产无限扩大；为了实现剩余价值,资本必须保持生产和消费的正确比例从而限制生产的无限扩大趋势,这两者共同构成了资本的矛盾本质.不难发现,这次国际金融危机的根源是资本矛盾本质决定下的生产相对过剩.资本矛盾命题具有重要的当代启示,即应当坚持资本和资本主义的分离、坚持基本经济制度的社会主义性质、坚持以科学发展观来规划和调整经济的发展道路和发展方向.     

水泥混凝土桥面铺装与一般路面结构力学机理对比分析

在结构特性上， 桥面铺装结构远比一般的路面结构复杂。 桥面板与沥青铺装层间的模量相差悬殊， 桥面混凝土结构挠度大， 桥面沥青铺装在车辆荷载作用下的受力状况与一般路面不同； 从桥面的温度差异来看， 桥面环境比路面环境也更为严苛； 因此， 桥面铺装在重载和制动力的双重作用下， 沥青铺装层与桥面之间承受较大剪应力和剪应变。 本文将总结以往桥面铺装结构力学分析研究成果， 提出桥面铺装结构力学指标， 为浙江省山区高速公路桥面沥青铺装结构设计提供理论依据。     

KHB型高压油脂润滑泵在汽车底盘集中润滑系统中的应用

主要介绍集中润滑在汽车底盘的重要性,重点分析中高压集中润滑系统在实际使用过程中更加节省油脂,为客户创造更多价值,阐述集中润滑系统的发展趋势,为汽车整车和零部件的研发工作提供参考。     

粉煤灰地层浅埋大断面连拱隧道预加固方式研究

由于粉煤灰地层本身工程性质较差,隧道开挖时不同工序及支护方式的变化也极易影响掌子面的稳定及支护结构的安全.本文结合盐坪坝隧道埋深浅、跨度大、穿越不良地层粉煤灰地层的特点,对浅埋暗挖大断面隧道工程中常用的地层预加固方式做简要介绍并分析其适用性,结合现场实际,提出了一种适用于粉煤灰地层大断面连拱隧道的预加固技术,主要采用高压旋喷桩对穿越粉煤灰地段实施地表加固,从现场施工情况来看,盐坪坝隧道现已成功贯通,期间没有发生掌子面坍塌、地表沉陷等情况.     

The identification and empirical characterization of vehicular (Lagrangian) fundamental diagrams in multilane traffic flow

Traditional macroscopic traffic flow modeling framework adopts the spatial–temporal coordinate system to analyze traffic flow dynamics. With such modeling and analysis paradigm, complications arise for traffic flow data collected from mobile sensors such as probe vehicles equipped with mobile phones, Bluetooth, and Global Positioning System devices. The vehicle‐based measurement technologies call for new modeling thoughts that address the unique features of moving measurements and explore their full potential. In this paper, we look into the concept of vehicular fundamental diagram (VFD) and discuss its engineering implications. VFD corresponds to a conventional fundamental diagram (FD) in the kinematic wave (KW) theory that adopts space–time coordinates. Similar to the regular FD in the KW theory, VFD encapsulates all traffic flow dynamics. In this paper, to demonstrate the full potential of VFD in interpreting multilane traffic flow dynamics, we generalize the classical Edie's formula and propose a direct approach of reconstructing VFD from traffic measurements in the vehicular coordinates. A smoothing algorithm is proposed to effectively reduce the nonphysical fluctuation of traffic states calculated from multilane vehicle trajectories. As an example, we apply the proposed methodology to explore the next‐generation simulation datasets and identify the existence and forms of shock waves in different coordinate systems. Our findings provide empirical justifications and further insight for the Lagrangian traffic flow theory and models when applied in practice. Copyright © 2015 John Wiley & Sons, Ltd.     

Labview应用程序开发中使用支持文件相对路径的有关问题

用Labview开发涉及支持文件读写的应用程序时,常会出现调试正常而可执行文件运行时找不到支持文件路径的错误。基于一简单示例,分析了产生此问题的原因并提供了解决问题的思路。     

载货汽车主气瓶不同气压时制动性能分析

汽车综合性能测试仪VGQT测试分析结果表明,货车在主制动气瓶压力不同时,各轴制动气室所能达到的最大压力也不相同[1],除此之外,本试验中N类载货汽车0型制动试验表明,主气瓶气压不同时,各轴气室制动压力变化曲线以及有效最大减速度MFDD也不相同。载货汽车绝大部分是用于长途运输,尤其是N2、N3类载货汽车,由于其满载质量大,长途运输中制动效能对于行驶安全性有着很大的影响,尤其在我国西南部山道纵横,长时间上下坡很容易造成制动器的热衰退,这是引起交通事故的主要诱因之一[2,3]。本文以实际试验结果为研究对象,分析了主气瓶在不同压力下各轴制动气室压力的变化以及0型制动试验中制动气压曲线的变化和有效最大减速度的变化,这对于行驶安全性和燃油经济性都有一定的意义,进而对排放和环境造成影响。     

不锈钢车体钝化工艺研究

针对轨道交通车辆在制造过程中,不锈钢车体表面的钝化膜因机加工、焊接等因素可能遭到破坏,导致不锈钢车体防腐能力下降的情况,详细介绍了不锈钢车体的钝化原理、钝化工艺及钝化效果的检测方法。经过柠檬酸钝化液钝化处理后,可有效去除车体表面游离铁和其他杂质,车体表面颜色均匀一致,提高了不锈钢车体的耐蚀性和美观性。     

两种跨平台航迹精度测评方法研究

跨平台航迹精度测评对多平台协同使用传感器航迹数据具有指导意义,论文介绍了相对于本平台距离/方位的测评方法(方法一)和空间距离精度的测评方法(方法二),从非线性坐标变换的角度分析了本平台位置对测评结果的影响,其中方法一的计算结果在两平台位置相差不大的情况下主要受被探测目标相对于这两个平台的方位角度差影响,方法二的计算结果则不受本平台位置的影响,因而后者更有意义。     

Development of knowledge based body structure concept design model

The purpose of this study is to propose a concept design process for an automotive body structure using technical information on the major joints and members of vehicles. First, in order to collect the technical information on major joints and members, 17 vehicles were selected using benchmark data. The collected technical information for the selected vehicles was the cross sectional shapes of each joint and member which were used for the analysis of joint stiffness, crashworthiness and static stiffness of the member to make a database along with cross section properties. This study applied a ‘What If Study’ technique to perform a concept design of an automotive body using the analyzed information and selected cross section meeting the design objectives. The criteria for the selection of the cross section were defined by subdividing the defined design objectives of an automotive body structure and constraints into members and joints. In order to configure an analysis model of an automotive body structure using the selected cross section, a shape parametric model was used and static stiffness, dynamic stiffness and crashworthiness were assessed to evaluate the configured automotive body structure. The evaluation result showed that the crashworthiness and static/dynamic stiffness were improved compared to an existing body structure. In addition, the weight of the body structure was reduced. Through this study, the process that can rapidly and effectively derive and evaluate the concept design of an automotive body structure was defined. It is expected that, henceforth, this process will be helpful for the study of automotive body structures.